Groundwater Extraction and On-Site treatment by UV Oxidation
- Groundwater is extracted from 13 wells at the site.
- Total flow rate from the network of wells ranges from 390 to 500 gpm.
- Extracted water was initially sent through a chemical precipitation step. This step has since been removed from the system.
- Treatment steps include: dual-media filtration, UV Oxidation, GAC treatment (polishing), pH adjustment, stripping for ammonia removal and neutralization.
- Treated water is discharged to an-onsite surface water body (Big Black Creek)
CERCLA and State
- ROD date - September 17, 1990
2869 (Industrial Organic Chemicals)
U.S. Army Corps of Engineers
Grand Haven Area Office
P.O. Box 629
Grand Haven, Michigan 49417
|Regulatory Points of Contact:|
USEPA Region V
77 West Jackson Blvd
Mail Code: SR6J
Chicago, Illinois 60604
P.O. Box 30426
Lansing, Michigan 48909
VOCs and SVOCs
- Benzene, Benzidine, 2-Chloroaniline, 1,2-Dichloroethene, Trichloroethene, 3,3-Dichlorobenzidine, Aniline, Vinyl Chloride
- Selected Maximum concentrations in µg/kg - Benzene (60,000), 2-Chloroaniline (63,000), Aniline (10,000), 3,3-Dichlorobenzidine (2,600)
Disposal of process wastes in 10 unlined impoundments at the site
Type/Quantity of Media Treated:
- 700 million gallons extracted since 1994.
- 7,500 pounds of organic contaminants removed from extracted groundwater
Purpose/Significance of Application:
The extraction and treatment system has successfully contained migration of contaminants from the site and consistently met discharge requirements since system startup in 1994.
Regulatory Requirements/Cleanup Goals:
The following list contains current discharge limits for selected contaminants. All limits have been established by MDEQ and are maximum allowable concentrations, based on weekly effluent sampling.
- Purgeable Halocarbons - 5 µg/L (each)
- Purgeable Aromatics - 5 µg/L (each)
- Aniline - 5 µg/L
- 2-Chloroaniline - 10 µg/L
- The extraction and treatment system is containing the groundwater contamination plume at the site.
- Contaminant concentrations in the treatment system effluent have been consistently below surface water discharge limitations for the site.
The total capital cost for construction of the treatment system was $12,200,000. Yearly O&M costs average $763,000. Over three years, the capital plus O&M costs translate to $19.61 per 1,000 gallons of groundwater treated, or $1,830 per pound of organic contaminants removed. Yearly O&M costs translate to $3.27 per 1000 gallons of groundwater treated, or $305 per pound of organic contaminants removed.
For approximately 20 years, chemical process waste liquids and sludge were routinely disposed in 10 unlined surface impoundments at the site. In addition, impoundment berms occasionally failed, releasing sludge into nearby surface water bodies. In 1978, thirteen extraction wells were installed at the site to collect contaminated groundwater down gradient of the impoundments. Collected water was treated in an existing system located at a nearby facility, and was subsequently sent the local POTW for additional treatment. A Record of Decision (ROD) was signed in September 1990, specifying construction of a new on-site treatment system with UV oxidation as the primary treatment technology.
Under direction of the USACE, treatability testing and treatment system design were performed in 1991 and 1992. In 1992 a contract was awarded for construction of the treatment system. In September 1994, construction of the system was completed and full-scale treatment was begun. The treatment system originally consisted of: metals precipitation pretreatment, dual media filtration, UV oxidation treatment for removal of organics, GAC treatment (polishing), pH adjustment, stripping to remove ammonia and neutralization. After one year of operation, the metals precipitation step was determined to be unnecessary, and was removed from the treatment train. Treated water is discharged to an on-site surface water body (Big Black Creek).
The treatment system is currently in operation and is successfully containing groundwater contamination at the site. It is estimated that significant reductions in groundwater contaminant concentrations will not be realized until the sources of contamination (impoundment soils and sludge) are removed or isolated.